Sensitivity study on the number of height levels used in a numerical weather model to determine the vertical profile of Cn2

Abstract

Accurate prediction of the vertical distribution of optical turbulence strength (see manuscript PDF for symbol) is essential for several applications, such as ground-to-satellite optical communications and astronomical seeing prediction. We have developed an algorithm that couples the calculation of (see manuscript PDF for symbol) profiles with the results of the Weather Research and Forecast Model (WRF), using the Tatarskii formula for (see manuscript PDF for symbol). The mixing length scale was identified as a critical parameter along with the gradients of potential temperature and wind speed. To determine the effects of the number of vertical levels used in the simulations and the effects of diurnal variations, we conducted a study using 100 to 500 levels in both daytime and nighttime simulations. We analyzed the results to identify differences and to suggest improvements in the calculations, taking into account the trade-off between longer simulation time and accuracy. We also compared our results to vertical profiles of (see manuscript PDF for symbol) derived from experimental data obtained from radiosonde ascents, for the Bergen radiosonde station in Germany. Our results contribute to refining the modelling of (see manuscript PDF for symbol) and improving the accuracy of the prediction, which will benefit various practical applications.